Positive effects of gastric bypass The currently most commonly used surgical method is the gastric bypass (RYGB), which has proven to be a highly effective method of achieving a great and permanent weight loss with an approximately 30-40% reduction in the weight, which is equivalent to 40-60% reduction of the overweight. Moreover RYGB has shown to provide complete remission of prior type 2 diabetes in up to 80% of cases at short observation time (up to 2 years after surgery) and about 50% remission at longer time follow-up (> 5 years).